Kangaroo burgers and steaks are sold in the UK as well, at Walkabouts (Australian themed bars). However, the reason it's such an issue is that a) the public is generally squeamish about non-conventional meats, b) the products weren't labelled properly, c) criminals acts were committed, and d) nobody knows what quality the meat was (we know that some of it contained potentially dangerous drugs). A lot of horses that are unfit for the food chain are being sold from the US into Latin American countries, who then ship that meat to the EU - the systems in place to ensure the quality of the meat are woefully inadequate and rely on the honesty of suppliers.

I'd have absolutely no problem with going into McDonald's and ordering a horse burger if they sold one but I want to know exactly what I'm ordering and that it is safe to eat.